Finger-wheel operated call trans



MW V

Aug. 7, 1951 Filed April 17, 1948 I 34 H. R. CLARKE I L.A. ELMER NW NT095 A. HERCKMANS 0. L. WALTER Z/W YMM A 7' TOR/v; Y

Aug. 7, 195] Filed April 17, 1948 H. R. CLARKE ET AL 2,563,581FINGER-WHEEL OPERATED CALL. TRANSMITTER HAVING LARGER NUMBER PLATE THANFINGER WHEEL 3 Sheets-Sheet 2 72-22% w v5/v r09 A, HERCKMA/VS 0.L.WALTERBY (/Q g- 1951 H. R, CLARKE ET AL 2,563,581

FINGER-WHEEL OPERATED CALL TRANSMITTER HAVING LARGER NUMBER PLATE THANFINGER WHEEL Filed April 17, 1948 3 Sheets-Sheet 5 L ll i 5a H.R.CLARKEO. L. WALTER A 7' TOPNEV Patented Aug. 7, 1951 *FINGER-WHEEL OPERATEDCALL TRANS- MITTER'HAVING LARGER NUMBER PLATE THAN FINGER WHEEL "HarryR. Clarke, Milburn, Lloyd A. Elmer, .Sum-

mit, Alfred 'Herckmans, Springfield, and Orville L. Walter, Maplewood,N. J., assignors to Bell Telephone Laboratories, Incorporated, New York,N. Y., a corporation 'of New York Application April 17, 1948, Serial No.21,618

This invention relates to telephone call trans ftio'n and so combined asto be readily accessible for adjustment and repair.

Another object of the invention is the provision of a'calltransmitter'ofthe finger-wheel operated type in which "the'wind-up or clockwiserotation of the finger wheel cause the collective operation of a pair ofcontact springs 'to prevent the "transmission of impulses and on itsreturn tonor- '=mal prevents the collective operation 'of said springstopermit a series of impulses to be transmitted.

r A further object of the invention is the provision of a calltransmitter of the finger-wheel operated type in which the number plateis of a substantially larger diameter than the finger wheel, isconcavo-convex in cross section and has its-indicia located beyond theperiphery of the finger wheel andin concentric rows which are concentricwith the finger wheel.

The call transmitter of this invention is of the finger-wheel type andutilizes a number plate having a diameter substantially larger indiameter than the finger wheel. The number plate is constructed ofmolded material, is substantiallycon- =3;

cavo-convex in cross section, and has the indicia thereon arranged inconcentric rows which are concentric with the finger wheel and locatedbe yond' the periphery of the finger wheel.

The operating mechanism of the transmitter is g;

"mounted on a suitable plate located in the rear *of the number plateand comprises a drivin shaft operatively connected to the finger wheeland having associated therewith suitable gears for driving a pulsingmechanism for operating:

suitable contact springs for transmitting, electrical impulses when thefinger wheel i restored to its normal position under the influence of acoil spring located in a recess in the supporting plate housing andoperatively connected to the driving shaft so'thatit is tensioned by thewindup or clockwise rotation of the finger wheel and "a speed regulatindevice for controlling the operation of "the finger wheel during itsreturn to normal, is operatively connected by suitable gears to thedriving shaft. The contact springs operated by the pulsing mechanism tosend out a predetermined number of electrical impulses, de-

pending upon the amount of rotation of the finger 5 Claims. (0]. llililll) wheel, are operated collectively on the wlnd-up or clockwisedirection of the finger wheel and are thereby prevented from sending outany electrical impulses. Upon the return of the finger wheel to itsnormal position under the influence of a suitable driving spring, meansassociated therewith prevents the collective operation of the springsthereby permitting a series of electrical impulses to be transmitted.

In the drawing:

Fig. '1 is a top assembly view shown with a number of operating partswith portions broken away;

Fig. 2 is a side assembly view;

Fig. 3 is a rear view shown with the operating mechanism in normalposition;

Fig. 4 is a vertical sectional view taken on line 4 l of Fig. 2;

Fig. 5 is a rear view of a detail showing the gear train connecting thepulsing cam and governor mechanism in a unit assembly;

Fig. 6 is a side view of the unit shown in Fig. 5; and

Figs. '7, 8, 9 and 10 are views of the pulsing cam and associatedpulsing spring in different operated. positions.

According to the construction of the call transmitter of this inventiona circular mounting plate in the form of a casting I0 is formed at itscenter portion with a hub element l I extending perpendicularly from thebottom wall 12 of a cupshaped recess to form therewith an annular spaceprovided for receiving a helical motor spring l3, the hub I I beingreinforced at its base by a collar portion l4 having a number of equallyspaced radially disposed notches [5, any one of which may be used forhooking a radially bent portion i6 of motor spring 13 so as to securethe desired tension adjustment of the sprin for the operation of thecall transmitter, as will be hereinafter :described in detail.

In the hub II is fitted a bushing I1 provided for receiving a shaft I8having an enlarged portion Is at its upper disposed end forming ashoulider portion resting on the flange of bushing H as best seen inFig. 4. The enlarged portion [9 of shaft l8 is provided with twodiametrically opposite flat surfaces forengagement with a similarlyshaped opening in a projection 22 formed with a disc member 20. Thisdisc has a downwardly extending cylindrical ridge portion 2| serving forholding this end of the motor spring IS in concentric relation to thehub ll, while a drilled hole in the disc 20 is provided for receivingthe opposite end 16X of motor spring l3 which is held in place by a lug23 oflset downwardly from the plane of disc 26 as best seen in Figs. 1and 4. The applicants discovered that maximum torque was obtained frommotor spring l3 when the end [6X of the spring was attached to the disc26 so as to coincide with the position of pinion 39 when the firstfinger hold was in registry with the finger stop ST as when transmittingdigit 1.

A finger wheel 24 is provided at its center portion with a substantiallyrectangular opening engaging the projection 22 of disc 26 while a nut 25serves to collectively secure the finger wheel 24, disc 20 and a springwasher 26 to shaft I8. A radial projection Z, see Fig. 1, projectsbeyond -the periphery of the disc 29 and cooperates with a radialextending portion ZI formed integral with the rim RI of the number plate19 to readily locate the finger wheel 24 in its adjusted positionrelative to afinger stop ST secured to the mounting plate ill in amanner which will be hereinafter described in detail. The opposite endof shaft 18 is formed with two diametrically disposed -flat surfaces forreceiving a similarly shaped opening in a gear 21, see Fig. 4, heldsecurely in position thereon by a nut 28 and a washer 29. Gear 21, asshown in Figs. 2, 3 and 4, meshes with a pinion 39 formed with or keyedon a shaft 3| for rotation as a unit with a gear 32. Gear 32 meshes witha pinion 33 best seen in-Figs. 2, 3. and 6 mounted for free rotation ona shaft 34 journaled at both ends in bearings in bridge pieces 35 and36'whichare held in spaced relation to each other by a pair of spacermembers 3! and 38 and screws 39, the bridge piece 36 having ofi'setportions 49 and 41 serving for removably securing the unit thus formedto the mounting plate I9 as by screws 42.

Pinion 33 is formed with a cylindrical portion 43, see Fig. 6, whichcooperates with a cylindrical portion 44 formed with or keyed on shaft34 and a coiled spring 45 to form a one-way efiective clutch foroperating the shaft 34. One end of this shaft projects from the bridgepiece 35 for securely mounting a yoke-shaped member 46, best seen inFigs. 3 and 5, each arm of which is provided with a laterally disposedstud 41 serving for pivotally receiving the fiy-weights W and WI movableby centrifugal force upon the rotation of shaft 34 for frictionallyengaging the inner disposed peripheral surface of a drum 48-securelymounted on the bridge piece 35 for controlling the operation of apulsing mechanism when actuated by the tension of the motor spring. Theflyweights W and WI are provided with inwardly extending arms 49 and 50which are notched at their ends to receive the ends of a retractilespring 5! and permits the tension on the fly-weights W and WI to beadjusted by bending these arms so as to increase or decrease the springtension as desired.

Gear 32 also meshes with a pinion 52 formed with a shaft 53 constructedof a non-metallic material, such as nylon, journaled in bridge pieces 35and 36 and on this shaft is mounted for rotation thereon by friction, aswill be hereinafter described in detail, an arm 54 of insulatingmaterial, such as nylon, movable with shaft 53 in one direction anangular distance determined by the engagement of a ridge 6| formed withthe hub of this arm with a stop 55 adjustably secured on the bridgepiece 35 by screw 39 and in the opposite direction of rotation of shaft53 by the engagement of arm 54 itself with an abutment afforded by theduplex end 3:, Figs. 2, '7, 8, 9 and 10, of a contact spring 56 V whichin turn cooperates with a contact spring 58 to form a so-called pulsingcontact P-Pl. Contact spring 56, as best seen in Fig. 10, is offset fromits secured end on a support which will be hereinafter described indetail and the portion ml of this spring bent back upon itself forengaging a cam 59 preferably formed integrally with shaft 53. Accordingto this construction the positioning of the contacts P and PI at a pointbetween their support 64 and cam 59 the so-called "Chatter of thecontacts has been effectively prevented resulting in more accurate breakand make operation of the pulsing mechanism.

Rotational movement is imparted to the arm 54 in conjunction with itssupporting shaft 53 by a substantially V-shaped spring 60, straddling areduced portion of the projection 6| and its free ends projecting beyondthe center of shaft 53 as best seen in Figs. 2, 6, '7, 8, 9 and 10 forengaging the latter with a predetermined tension. The pulsing springs 56and 58 terminate at one of their ends as above mentioned in the form ofduplex prongs having cooperating contact points P and PI while theopposite end of contact springs 56 and 58, as best seen in Figs. 3 and4, are held securely in parallel assembled relation to each other andspring 56 in relation to its actuating pulsing cam 59 by two clampingplatesv 62 and 63 of insulating material, intum held securely on a base64 formed with casting In by the tightening action of screws 65.Similar1y,,a pair of parallelly disposed springs 66 and 61 are clampedbetween the plates 52 and 63 and extend therefrom for operation by astud 68', see Figs. 3 and 4, of insulating material carried by gear 21engaging a lug portion 69 formed with spring 61 to perform a functionwell known in the telephone art and which forms no part of the presentinvention, the contact springs 56, 58, and springs 66 and 61 beingformed with lugs at Ll, L2, L3 and L4, respectively, protruding from theplate 53 for connection-with the telephone apparatus not shown.

The number plate '15 which is constructed of transparent material, forexample Lucite, is formed with a concavo-convex cross-section and isprovided at its under-disposed or convex side with concentricallydisposed reinforcing rim portions R2 and R3, and at its concave sidewith a rim'Rl, the rim portions R2 and B3 forming with-the under-side ofthe plate ll! an annular channel or groove in which groups of lettersand digits or other indicia are located in angular spaced relation toeach other and in radial relation with the finger holds of the fingerwheel 24. The groups of letters and digits are formed or produced in thecastingof the number plate by a, mold having in relief the groups ofletters anddigits to be reproduced as cavities in the number plate, suchcavities being filled with a white paint, and the undersurface ofthe'annular recess painted black, for example, which colors have beenfound in actual use to produce a suitable contrasting effect, theannular groove .formed by ridges R2 and R3 being disposed concentric toand beyond the peripheral edge of the finger wheel 24, thus effectivelyavoiding the eclipsing of the indicia or the casting of shadows on thenumber plate from the finger Wheel.

The circular mounting plate [0' is formed with a downwardly extendingprojection 89, best seen in Figs. 2 and 3, and a rectangularly-shapedopens reg ste g wit a similarly sh ped op imthe .number ;.plate: 101:for: receiving the secure: ingsportion .ofsa fingerestop. ST. heldiin"placezasi by a screwiti l .the finger stopiST thus cooperate:

in'gvlwith the registering. openings: in. .the mounting-plated llandinthe number platei'lil'to-readily locate :the latter in adjustedposition-relative to the-fingerwheel 24. preliminary tothe securing;

of rtheinumber'platenon the casing 19 sasibyua pluralityofiscrews-SVh'best seen in 'Fi'gs.:l and 4. Th'ejfirigerwheel 24 isprovidedwithzitwo .dia-

metrically opposite rectangular openings Y and Yl 'having shoulderportions as best seen in'Fi'g'.

4 engaged by prongs II and f2 projecting from: the edge of acylindrically-shap-ed card holder-15 for: holdingthelatter hooked to thefinger Wheel zdiithiscard holder'having a downwardly turned edg'e forholdinga disc memberl'5 of transparent material. aninstruction cardnitgametal disc 11" and a supporting ring id'ofresilient material havingits"innerdisposed peripheral edge =hearingagainst the finger wheel 24 anditsouterdisposed :peripheral: edge against the metallic disc'l'li'ifresilientring'm having diametrically oppo site .lugiportionsliifitted insthe openings Y'anri Y'lof: the finger wheel so as toprevent relative movement of :the elementsin the assembly thus formed'relative tothe cardholder 13* and there fore relative to thefingerwheel,.whi1e' reinforc ing the'prongs 1| and i2 against a force tendingto flex these. prongs as-for the removal of the cardholder-from thefingerewheel.

In .theoperation of the call transmitter of this invention the manualoperation of the finger wheel 24 in a clockwise;direction from any oneof .thegroups of letters or digits carried by the number plate 7!! tothe finger stop S'Ii's, effective to rotate the shaft l8 and therebytension'the motor spring 3. The rotation of gear 21 keyed on shaftls isimparted to -pinion as and keyed on shaft 3! and to pinions stand 52Rotation :of pinion 33 in this direction of rotation isr-ineffective'torotate the shaft 34 becausesof thesunwinding of clutch spring 45v ondrumss andsM-p Upon the rotation of pinion carried by shaft 53=andtherefore the rotation of. pulsing cam-59=:=in the direction indicatedbythe'arrows in Figs-. 3 and '7, that is, during the so-called selectivemovement of the finger wheel, the arm 54 is moved out of registeringrelation from the end portion ofpulsing spring Eihthe cam 59 at thetime; holding the pulsing spring 55 in the' operated positionandthroughrthe .engagementof contact points P and PI, the contact spring 55holding its associated contact spring 58 raised a small distance beyondthe apex of arm 54 so that the arm 54 is rotated because of thefrictional effect of spring EU on shaft 53. Upon the continued movementof shaft 53 the ridge 6! of arm 54 abuts against the stop 55 while thecontinued rotation of cams 52 permits the collective operation of thenow closed contact springs 56 and 58 until the finger of the operatorreaches the stop ST projecting radially a small distance over the fingerwheel 24. Upon the release of the finger wheel by the operator thepulsing mechanism is returned to non-operated or normal position by thetension of motor spring [3 but under control of the governor mechanismnow connected to pinion 33 by the tightening efiect of clutch spring 45on drum 43 formed with this pinion and on drum 44 keyed on shaft 34 asabove de scribed.

Rotation of shaft 53 in the direction opposite to that indicated by thearrow in Fig. 7, the cam 59 in its first turn in this directioncollectively operates; the rclosed-iicontactafi Stand .58 through, the.contact points P and.- P lr'thlls. permitting the a art; topmove underthe =free -end .of contact 58i-"il'l abutment;with. the;..stop affordedby the... end. of the;duplex-.-arms a: formed-with pulsing spring 56preparatory toxthe second turn of cam.

59. to.gcause-thaopening of the contacts PPI as; indicated -in1;Fig. 8while the pulsing spring. 58 is :retainedin its operatedposition. by.armjd but the pulsing spring 56 which is normally ten-e sionedagainstqtheyicamijfl .follows the contour of: thiszcam causing the firstinterruption ofthe telephone: line by opening, the contact.P.P I; thenegativing ofthefirstturn of -cam -59 being. for. titer-purpose. of.'obtaining a given lapse of time ins-the,fast successive: dialing ofdigit 1, for exam:

pie-,asaasto: permit the proper operation of the. so calleidselector-and connector switches at the. telephone exchange;under-control of the transmitter; 1

Uponthe; return :oftthe-finger wheel-211. to its normalnomoperatedposition the armZ carried by disomemher-fifl on-shaft l8 engages thestop 7 Z!tearriedby,theinumber plate I0 and the transenutter-is.nowwreadyifor a succeeding operation.

Theroncave side-:ofthe:numberaplate1B from which the indicia,are::.visually, -observed facili-v tat-es the selection of. the.desiredsymbol, while the.-:locati0nr:of such symbols in a circular rowconcentric-and beyond thei'peripheral edge of the finger. wheelieffectivelyrprevents shadows from.. thefinger ,wheel .reaching' andobstructing the symbols carried bythenumber plate.

What is claimed 1. VA :.cal11 1. transmitter :comprising; a circular--mounting plate; a cylindricallyrshaped .emboss portiondisposed;centrallrthereof; a hub portion.

formedv concentrically; to' said; embossportion :to fornrran.annular:rspacecgtherebetween, a shaft mountedfor rotationinsaidthubportion,a coiled motor spring fitted in theiannul-arspace.between:

saidembossxandsaid hub; portions;.a disc; memberkeyed ononeend ofsaidshaft havingmeans.

for.securely.l receivingronezend ofrrsaid. spring;

means formediwith said hubportion :for securely." receiving: theopposite endof said spring, a finger.

wheel keyed on ."said disc. memberoperably. for tensioning. said motorspring, a pulsing mecha-v nism, includingaa .cam::.operatively connectedto: id fi -W e l,- a pair of. contact springs one, of saidspringsinengagement withthe surfaceof.

said-cam .for actuating. collectively by the camof said mechanism uponthe manual operation of said finger wheel, for tensioning said motorspring, and a second cam rotatably mounted adjacent said first cam andfrictionally actuated by said mechanism under the tension of said motorspring in position for preventing the operation of one of said springsduring the operation of the other spring for transmitting the call.

2. A call transmitter comprising a circular mounting plate in the formof a casting having a hub portion formed centrally thereof, a shaftrotatably mounted in said hub portion, a finger wheel carried by saidshaft, a finger stop secured to said mounting plate, a number plate of alarger diameter than that of said finger wheel and having aconcavo-convex cross section secured to said mounting plate and havinggroups of symbols disposed beyond the peripheral edge of said fingerwheel, a motor spring tensioned by the clockwise rotation of said fingerwheel during the selective operation thereof relative to said symbols, apulsing mechanism including a cam operatively connected to said fingerwheel, a pair of contact springs, one of said springs in constantengagement with the surface of said cam for actuating collectively saidcontact springs, said cam actuated by the tension of said motor springfor transmitting a number of pulses corresponding to the selectivemovement of said finger wheel, and means to render the operation of saidfinger wheel during the tensioning of said spring ineffective relativeto said pulsing mechanism.

3. A call transmitter comprising a mounting in the form of a casting, ahub portion carried by said mounting, a shaft rotatably fitted in saidhub portion, a motor spring disposed in position concentric to said hubportion, a disc member keyed on one end of said shaft having means forsecurely receiving one end of said spring, means carried by said hubportion for receiving the opposite end of said spring, a finger wheelkeyed on said disc member for tensioning said motor spring upon therotation of said finger wheel, a number plate secured to said mounting,means carried by said number plate cooperating with means carried bysaid disc for limiting the movement of said finger Wheel under thetension of said motor spring, a driving gear keyed on the opposite endof said shaft, a driven gear train mechanism comprising a plurality ofpinions actuated by the driving gear keyed on said shaft, a pulsing cam'operatively connected to and actuated by said gear mechanism, a pulsingcontact, and a sedond cam rotatably mounted adjacent said first cam andoperable upon the movement of said first cam to render the operation ofthe latter ineffective relative to said pulsing contact during themanual operation of said finger wheel, said friction means operatingupon the movement of said cam following the reverse movementv of saidfinger wheel by the tension of said motor spring to cause the operationof said contact by the rotation of said cam.

4. A call transmitter comprising a mounting, a shaft arranged forrotation on said mounting, a finger wheel and a gear keyed on saidshaft, a number plate secured to said mounting, having a plurality ofgroups of letters and digits disposed in angular spaced relation to eachother, a governor, a pulsing cam, a gear mechanism operativelyconnecting said governor and said cam to said shaft, a frame for saidgear mechanism, said cam and said governor detachably secured to saidmounting by threaded fastening means, pulsing springs secured to saidmounting, one of said pulsing springs having means disposed in operablerelation with said cam, means for limiting the operation of said fingerwheel from any one of the groups of letters and numbers on said numberplate in one direction, a motor spring tensioned by the operation ofsaid wheel for rotating the latter in the opposite direction to causethe operation of said pulsing springs, and means carried by said shaftengaging means carried by said number plate for stopping the movement ofsaid finger wheel following the operation or said pulsing springs bysaid cam under control of said governor.

5. A call transmitter of the finger-wheel type comprising, a numberplate, a finger-wheel mounted above said number plate and in spacedrelation thereto, said finger-wheel being substantially smaller indiameter than said number plate, said number plate havin aconcavo-convex cross section, the indicia on said number plate arrangedin concentric rows which are concentric with the finger Wheel, beyondthe periphery of the finger wheel and in radial alignment with the holesin the finger wheel, said number plate secured to the mounting plateupon which the transmitter mechanism is mounted and which is operativelyconnected to said finger wheel.

HARRY R. CLARKE.

LLOYD A. ELMER. ALFRED HERCKMANS. ORVILLE L. WALTER.

, REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,456,602 Kaisling May 29, 19231,501,281 Ide July 15, 1924 1,543,662 Booth June 30, 1925 1,556,906Blessing Oct. 13, 1925 1,580,943 Baker Apr. 13, 1926 2,206,224 FieldJuly 2, 1940 2,244,609 Cosgrove June 3, 1941 2,394,360 Bosh Feb, 5, 19462,448,647 Wood Sept. 7, 1948 FOREIGN PATENTS Number Country Date 308,385Great Britain Mar. 28, 1929

